Methods The ERα and ERβ in levator ani muscle and pelvic floor structure of premenopausal and postmenopausal SUI patients were detected by immunohistochemical staining and Western blot.

RESULT Levator ani muscle is composed by layers of many tiny bandlike muscle bundles, which spread naturally into a whole piece of muscle.

The result showed that:①The levator ani muscle will draw away the external sphincter and the puborectalis muscle when perineum descending by equal long contraction, this makes the internal sphincter on the free state;② The puborectal muscle is the real muscle of lifting the anal canal and the perineum.

Objective To study the correlation of morphological and functional changes of the levator animucle muscle and stress urinary incontinence(SUI);to get MRI diagnostic criteria of SUI and to give a possible explanation for SUI mechanisms.

AIM: To establish the three-dimensional model of feminine pelvic floor,the complex geometric configuration of levator ani,pelvic and obturator internus,and to provide an initial preparatory work for further research on the mechanical mechanism of the feminine pelvic floor and the pathogenesis of the pelvic floor dysfunction from the perspective of the mechanics.

RESULTS: An independent three-dimensional geometric structure was obtained respectively for the obturator internus,levator ani,bladder,urethra,vagina and rectum,which exactly manifested the relative position of their anatomical structure.